2025-03-21 11:09:14 -06:00

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Antiderivatives

An antiderivative is useful when you know the rate of change, and you want to find a point from that rate of change

A function F is said to be an antiderivative of f if F'(x) = f(x)

Notation

The collection of all antiderivatives of a function f is referred to as the indefinite integral of f with respect to $x$, and is denoted by:

\int f(x) dx

Examples

Find the antiderivative of the function y = x^2

  1. We know that to find the derivative of the above function, you'd multiply by the exponent (2), and subtract 1 from the exponent.
  2. To perform this operation in reverse:
    1. Add 1 to the exponent
    2. Multiply by \dfrac{1}{n + 1}
  3. This gives us an antiderivative of \dfrac{1}{3}x^3
  4. To check our work, work backwards.
  5. The derivative of \dfrac{1}{3}x^3 is \dfrac{1}{3} (3x^2)
  6. = \dfrac{3}{3} x^2

Formulas

Differentiation Formula Integration Formula
\dfrac{d}{dx} x^n = nx^{x-1} \int x^n dx = \dfrac{1}{n+1}x^{n+1}+ C for n \ne -1
\dfrac{d}{dx} kx = k \int k \space dx = kx + C
\dfrac{d}{dx} \ln \|x\| = \dfrac{1}{x}
\int \dfrac{1}{x}dx = \ln \|x\| + C
\dfrac{d}{dx} e^x = e^x
\int e^x dx = e^x + C
\dfrac{d}{dx} a^x = (\ln{a}) a^x \int a^xdx = \ln \|x\| + C
\dfrac{d}{dx} \sin x = \cos x \int \cos(x) dx = \sin (x) + C
\dfrac{d}{dx} \cos x = -\sin x \int \sin(x)dx = \sin x + C
\dfrac{d}{dx} \tan{x} = \sec^2 x \int \sec^2(x)dx = \tan(x) + C
\dfrac{d}{dx} \sec x = \sec x \tan x \int sec^2(x) dx = \sec(x) + C
\dfrac{d}{dx} \sin^{-1} x = \dfrac{1}{\sqrt{1-x^2}} \int \sec(x) \tan(x) dx = \sec x + C
\dfrac{d}{dx} \tan^{-1} x = \dfrac{1}{1+x^2} \int \dfrac{1}{\sqrt{1+x^2}}dx = \tan^{-1}x + C
\dfrac{d}{dx} k f(x) = k f'(x) \int k*f(x)dx = k\int f(x)dx
\dfrac{d}{dx} f(x) \pm g(x) = f'(x) \pm g'(x) \int (f(x) \pm g(x))dx = \int f(x) dx \pm \int g(x) dx